Can I call my ex girlfriend's dad?

My girlfriend of a year and three months broke up with me one month ago and within a week already moved on to a new boyfriend and still together. I've done a lot of thought and I know what I did wrong (I was moving too slow), what she did wrong (didn't communicate that thought) and what I can do better in the future (with we specificity and without). Anyways her parents seemed to like me and I wanted to call her dad and just see how things are going. Her parents and I seemed to have a good relationship. I do want to fix my relationship with my ex and I love her dearly. I did treat her right and I don't understand how she's so happy now with a guy totally different from me. Would it be a bad or good to call her dad when she wouldn't be home?
Can I call my ex girlfriend's dad?
Add Opinion